Relief valve



March 27, 1945. R. vSTEVENSOIN ET AL 2,372,631

RELIEF VALVE Filed Sept. 18, 1942 A @CU/Vl (lL/)TOR Patented Mar. 27, 1945 RELIEF VALVE Robert Stevenson and Alexander W. Keema, Providence, R. I., assignors to Merit Engineering, Inc., a corporation oi Rhode Island Application September 18, 1942, Serial No. 458,902

l mined pressure. An exit I6 from chamber II is 1 Claim.

This invention relates to a relief valve such as may be used to control the storing of uid at a. certain predetermined pressure in a reservoir or the like for operating some work unit.

One of the objects of this invention is to provide a valve which will be so arranged that a light` spring may be utilized for controlling the valve.

Another object of this invention is to provide a simply controlled valve and yet one which will operate satisfactorily under high pressures.

Another object of the invention is to provide a valve which will be partially balanced by the pressure which it controls with a spring to cause movement of the plunger in one direction to close the valve against a diiierential pressure which may be overcome upon building up of the pressure.

With these and other objects in View, the invention consists of certain novel features of construction, as will be more fully described and particularly pointed out in the appended claim.

Fig. l is a top plan view of the valve;

Fig. 2 is a central` section view;

Fig. 3 is a fragmental detail on an enlarged scale from that shown in Fig. 2 and illustrating diagrammatically the difference in diameters of the effective areas upon which the :duid pressure exerts force;

Fig. 4 is an elevation showing an arrangement for supplying and of storing of fluid at pressures of different values )Troniy a single pump.

In proceeding with this invention we have prom vided a plunger having a longitudinal conduit so that the pressure to which the valve is exposed presses against both ends of the movable plunger whereby the differential of the efiective diameters against 'whichthe fluid presses will govern the movement of the plunger, it kbeing desirable that the diameter against which tlie/ pressure acts to move the plunger to closed position shall be less than the area tending to open the plunger and that this lesser diameter will be supplemented by a light spring pressing in an amount to just overcome the larger area or diameter until the uid pressure builds up to a predetermined extent when the plunger will move to compress the spring.

With reference to the drawing, I design/ailesv the body of generally cylindrical construction having a cylindrical bore ii, Trestricted as at l2 to provide a beveled valve seat I3 from which restriction there is an entrance opening I4 to the chamber `II which connects with the conduit I5 along which fluid is passed from the supply pump provided while at the upper end of the cylindrical chamber II's lining sleeve l1 is inserted and is heldin place by a closure cap I8 bolted to the body as at; I9 with heads 20 having slots 2l engaging the flange 22 of the body I0.

A piston 23 slidably ts lining I1 and is provided with grooves ls and packing la to prevent passage of the fluid along the surface of the piston between it and the lining I1, The piston is reduced in diameter as at 24 while at its lower end it is bevel shape as at 25 to llt the valve seat I3. The longitudinal bore 26 is provided extending throughout the axial length of the piston and at its upper end the piston is provided with an enlarged bore 2l to receive spring 28 which abuts at the lower end of this bore as at 29 and also abuts the collar 30 on the threaded plug 3| which thre dingly engages the cap I8 and is packed agaist leakage as at 32 while it is held in adjustejd position by the check nut 33. The lower end of this plug is reduced; to provide a guide 34 for the spring.

The uid which is provided in conduit I5 passes through the bore 26 and will press upon the top of the plunger 3S and will also press upon the lower end of the plunger 36. The relative diameters of the ends of the plunger are illustrated by A and B (see Fig. 3), it being noted that the diameter B is greater than the fdiameter A. Thus the greater force is exerted tending to move the plunger from its seat but by reason of the spring 2E this force is overcome at certain predetermined pressure conditions and thus the plunger will enage the seat I3 and be maintained thereagainst by a light spring pressure. However, when the pressure rises beyond the predetermined point at which the spring 28 is set by means of the adjustment 3l the diierential will increase and be such as to exceed the pressure of the area. A plus the spring and move the plunger from its seat. 'I'he areas A and B maybe varied to supply the diierent conditions necessary for operation.

This relief valve which we have provided is shown hooked up in multiple in Fig. 4 and as a.

whole is designated 40, 40', 40". The conduit 4I extends from the pump through the conduit I5 of the valve to supply fluid. to an accumulator 42 which for the sake of illustration may be assumeddesired to accumulate the fluid at 1,000

lbs. Accordingly, the spring 28 in the relief valve v will be set so that when the pressure of 1,000 lbs. l is provided in the accumulator 42 the valve will to the reservoir for storing the tluidand along f which iluid will pass/until it exceeds-a predeteropen. The fluid wm then pass through conduit 43 tothe next vvalve I0' and will pass 4through the conduit `l5 to supply the accumulator 44 with fluid, for example at 500 lbs. pressure. The spring 28 of this valve 40' will be set to permit the plunger to open when a pressure of 500 lbs. of'uid is provided in the accumulator 44 so Aas to communicate with the conduit 45 which conducts the fluid to the valve 4.0i' where the fluid will pass through the conduit l5 to the accumulator 46 which will be desired to accumulate fluid for example at 100 lbs. Thus, the spring 28 of the valve 40" will be set to open at 100 lbs. so that the conduit 41 will convey fluid back to the pump or to some other relief source when the pressure in the accumulator 46 has reached 100 lbs. By this arrangement from a single pump we may supply accumulators at varying pressures depending upon the` setting of the relief valve which we provide.

We claim:

'In a relief valve, a one-piece body provided with a cylindrical bore reduced at one end to form an inlet having a shoulder forming a valve seat, a plunger slidable in said bore and having a head portion at one end engaging said seat and provided at the other end thereof with a. piston having a recess opening in the end thereof, said plunger being provided with an axial conduit from said valve seat engaging portion to said recess subjecting its opposite end to the pressure in the inlet, whereby the said pressure to be relieved will press upon the ends of said plunger in accordance with the differential of the diameters of the said ends of the plunger exposed to said pressure, the diameter of the piston being,`

less than the effective diameter of the head, a sleeve mounted in the cylindrical bore for slidably receiving said piston, a, cap engaging said sleeve and closing said cylindrical bore, a spring in said recess additionally urging the plunger toward the valve seat and exerting sufllcient force to maintain the plunger in closed condition until the pressure inthe inlet increases to a predetermined extent to cause the pressure differential to overcome the added spring pressure and the iluid pressure on the plunger to move the plunger from its seat, an abutment engaging one end of said spring, a, threaded member extending through the cap operable for adjusting the pressure yof said spring and having one end engaging said abutment and having its other end extending outwardly of said ROBERT STEVENSON. ALEXANDER W. KEEMA. 

